110KV Lightning Arrester

I. Product Overview

The product mainly consists of zinc oxide valve, pressure equalizing cover, shell, monitor for arrester, pot insulator and electrical connector. Its main component, the zinc oxide valve, is enclosed in a grounded metal casing. One end is connected to the ground through the arrester monitor, and the other end is connected to the electrical circuit of the closed electrical appliance through the electrical connection. The inside of the housing is filled with 0.4MPa to 0.50MPa SF6 gas as the insulating medium, and the product has excellent performance. It is mainly used to protect 110KV system GIS combination electrical equipment from lightning, atmospheric overvoltage and overvoltage protection.

II. Adopt standard

GB11032-2000 "Exchangeless Metal Oxide Surge Arrester"

JB/T 7617-94 "Sulfur Hexafluoride Tank Type AC Intermittent Metal Oxide Surge Arrester"

III. Conditions of Use

a) Installation site: indoor/outdoor;

b) The ambient temperature is not higher than +40 °C, not lower than -40 °C;

c) The radiation intensity of sunlight is 1.1 kW/m2;

d) The altitude does not exceed 2000m;

e) The frequency of the power supply is not less than 48Hz and does not exceed 62Hz;

f) The power frequency voltage applied between the arrester terminals for a long time shall not exceed the allowable voltage of the arrester;

g) earthquake intensity of 8 degrees and below;

h) The maximum wind speed does not exceed 35m/s

IV. The main features of the arrester

1. Excellent protection characteristics 　　

The zinc oxide valve plate has excellent nonlinear volt-ampere characteristics. Its volt-ampere characteristic curve is shown in Figure 1. When the system has an overvoltage, the zinc oxide valve plate presents a low resistance state (that is, a conducting state). Under the condition of high resistance, the current flowing in the arrester is very small, which almost insulates the system from the earth. It is precisely this characteristic of zinc oxide that makes the oxide arrester for protection. When the atmosphere (lightning), operating shock or other overvoltage occurs in the substation, the oxide arrester first releases the overvoltage energy, and limits the overvoltage amplitude to the allowable value range that the insulation of the protected electrical equipment can withstand, and leaves some After a certain safety margin, the oxide arrester resumes its high resistance state, allowing the power system to work normally.

2. Large flow capacity

The current capacity of the metal oxide arrester indicates that the arrester has the ability to absorb various lightning overvoltages and operate overvoltage energy.

3. Strong power frequency tolerance

In the power system, due to various reasons, such as single-phase grounding, long-line capacitance effects and charge dumping, etc., it will cause the rise of power frequency voltage or the generation of transient overvoltage with high amplitude. Therefore, the arrester has the ability to withstand a certain period of time. The ability to increase the power frequency voltage is the power frequency overvoltage withstand time characteristic of the arrester.

4. Good dirt resistance

The gapless metal oxide arrester has high pollution resistance, because it does not need to consider the impact on the gap discharge voltage.

V. Main technical parameters of 110kV three-phase common tank type metal arrester for GIS